{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-43327", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-05-01T14:12:56.002Z", "datePublished": "2026-05-08T13:31:12.896Z", "dateUpdated": "2026-05-23T16:06:42.428Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-05-23T16:06:42.428Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nUSB: dummy-hcd: Fix locking/synchronization error\n\nSyzbot testing was able to provoke an addressing exception and crash\nin the usb_gadget_udc_reset() routine in\ndrivers/usb/gadgets/udc/core.c, resulting from the fact that the\nroutine was called with a second (\"driver\") argument of NULL. The bad\ncaller was set_link_state() in dummy_hcd.c, and the problem arose\nbecause of a race between a USB reset and driver unbind.\n\nThese sorts of races were not supposed to be possible; commit\n7dbd8f4cabd9 (\"USB: dummy-hcd: Fix erroneous synchronization change\"),\nalong with a few followup commits, was written specifically to prevent\nthem. As it turns out, there are (at least) two errors remaining in\nthe code. Another patch will address the second error; this one is\nconcerned with the first.\n\nThe error responsible for the syzbot crash occurred because the\nstop_activity() routine will sometimes drop and then re-acquire the\ndum->lock spinlock. A call to stop_activity() occurs in\nset_link_state() when handling an emulated USB reset, after the test\nof dum->ints_enabled and before the increment of dum->callback_usage.\nThis allowed another thread (doing a driver unbind) to sneak in and\ngrab the spinlock, and then clear dum->ints_enabled and dum->driver.\nNormally this other thread would have to wait for dum->callback_usage\nto go down to 0 before it would clear dum->driver, but in this case it\ndidn't have to wait since dum->callback_usage had not yet been\nincremented.\n\nThe fix is to increment dum->callback_usage _before_ calling\nstop_activity() instead of after. Then the thread doing the unbind\nwill not clear dum->driver until after the call to\nusb_gadget_udc_reset() safely returns and dum->callback_usage has been\ndecremented again." } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/usb/gadget/udc/dummy_hcd.c" ], "versions": [ { "version": "7dbd8f4cabd96db5a50513de9d83a8105a5ffc81", "lessThan": "6350c7dd33ab481ef41c931a238361490c32d15c", "status": "affected", "versionType": "git" }, { "version": "7dbd8f4cabd96db5a50513de9d83a8105a5ffc81", "lessThan": "cc97fb5969177cccce2e23b31298df220fc7570d", "status": "affected", "versionType": "git" }, { "version": "7dbd8f4cabd96db5a50513de9d83a8105a5ffc81", "lessThan": "218886b2ef2dea7627d3700ab0abaf4bf9d1161f", "status": "affected", "versionType": "git" }, { "version": "7dbd8f4cabd96db5a50513de9d83a8105a5ffc81", "lessThan": "791966f85b439b261bf19865cf1c07c065ffb4b4", "status": "affected", "versionType": "git" }, { "version": "7dbd8f4cabd96db5a50513de9d83a8105a5ffc81", "lessThan": "805b1833d6ed6da5086e610578a28e71bb54fbbb", "status": "affected", "versionType": "git" }, { "version": "7dbd8f4cabd96db5a50513de9d83a8105a5ffc81", "lessThan": "efbd9441f1e769a7aae1813d497cec09cbdff031", "status": "affected", "versionType": "git" }, { "version": "7dbd8f4cabd96db5a50513de9d83a8105a5ffc81", "lessThan": "69ab97a693251d6a6093e630060a3c744fd58524", "status": "affected", "versionType": "git" }, { "version": "7dbd8f4cabd96db5a50513de9d83a8105a5ffc81", "lessThan": "616a63ff495df12863692ab3f9f7b84e3fa7a66d", "status": "affected", "versionType": "git" }, { "version": "7b416b9dac6ede26d4ca0c1a88b448b543623ff3", "status": "affected", "versionType": "git" }, { "version": "8590bc1da625dd4a589eac0fc3aa3cf4f400424d", "status": "affected", "versionType": "git" }, { "version": "a867d5b932ac4911d3f8a1e63505061b0c81f889", "status": "affected", "versionType": "git" }, { "version": "e84b4a008365b7edbd842a063ae28d040a98db25", "status": "affected", "versionType": "git" }, { "version": "e39b17143a5b5aac81f066d455e5d3a9877eb3ae", "status": "affected", "versionType": "git" }, { "version": "4f8ae1fcb0dfbb72a7678f81bf01fb7fc85c6715", "status": "affected", "versionType": "git" }, { "version": "3.2.97", "lessThan": "3.3", "status": "affected", "versionType": "semver" }, { "version": "3.16.52", "lessThan": "3.17", "status": "affected", "versionType": "semver" }, { "version": "4.1.46", "lessThan": "4.2", "status": "affected", "versionType": "semver" }, { "version": "4.4.92", "lessThan": "4.5", "status": "affected", "versionType": "semver" }, { "version": "4.9.55", "lessThan": "4.10", "status": "affected", "versionType": "semver" }, { "version": "4.13.6", "lessThan": "4.14", "status": "affected", "versionType": "semver" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/usb/gadget/udc/dummy_hcd.c" ], "versions": [ { "version": "4.14", "status": "affected" }, { "version": "0", "lessThan": "4.14", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.253", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.203", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.168", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.134", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.81", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.22", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.19.12", "lessThanOrEqual": "6.19.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.0", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.14", "versionEndExcluding": "5.10.253" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.14", "versionEndExcluding": "5.15.203" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.14", "versionEndExcluding": "6.1.168" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.14", "versionEndExcluding": "6.6.134" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.14", "versionEndExcluding": "6.12.81" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.14", "versionEndExcluding": "6.18.22" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.14", "versionEndExcluding": "6.19.12" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.14", "versionEndExcluding": "7.0" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.2.97" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.16.52" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.1.46" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.4.92" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.9.55" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.13.6" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/6350c7dd33ab481ef41c931a238361490c32d15c" }, { "url": "https://git.kernel.org/stable/c/cc97fb5969177cccce2e23b31298df220fc7570d" }, { "url": "https://git.kernel.org/stable/c/218886b2ef2dea7627d3700ab0abaf4bf9d1161f" }, { "url": "https://git.kernel.org/stable/c/791966f85b439b261bf19865cf1c07c065ffb4b4" }, { "url": "https://git.kernel.org/stable/c/805b1833d6ed6da5086e610578a28e71bb54fbbb" }, { "url": "https://git.kernel.org/stable/c/efbd9441f1e769a7aae1813d497cec09cbdff031" }, { "url": "https://git.kernel.org/stable/c/69ab97a693251d6a6093e630060a3c744fd58524" }, { "url": "https://git.kernel.org/stable/c/616a63ff495df12863692ab3f9f7b84e3fa7a66d" } ], "title": "USB: dummy-hcd: Fix locking/synchronization error", "x_generator": { "engine": "bippy-1.2.0" } } } }